Instructors who have never taught with Wikipedia before will need some assistance before they're able to plan a good assignment, so you should build in a specific orientation step for instructors participating in your pilot. If you're starting in a small geographic region, it may be worthwhile to bring the instructors together in-person; they'll be able to have colleagues to reach out to for ideas around assignment design or problems that crop up — and potentially to write a journal article about their experiences with the program after you've finished, which will look good on their CVs.
Most instructors will not be familiar with wiki code or editing Wikipedia, so you'll want to cover wiki basics as well as best practices in assignment design. The online training for educators offers an overview of topics most instructors need to know before using Wikipedia as a teaching tool in their classroom. You're encouraged to translate and adapt the online training as needed for your country's education system and your language Wikipedia. See the documentation on Meta for details on how to port the trainings to another wiki.